Hydraulic machine tool



Jan; 19, 1943.

s. w. CURTIS HYDRAULIC MACHINE TOOL Fild June 6, 1941 4 Sheets-Sheet l 6 f 1 2 "EFF; L-.. a A ,4 v "W w j n :I n

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Filed-June 6, 1941 4 Sheet s-Sheet 2 9 2744A ATTORNEYS Jan. 19, 1943. F. w. CURTIS 2,30

HYDRAULIC MACHINE TOOL Filed June 6, 1941 4 Sheets-Sheet a INVENTOR ATTORNEYS Patented Jan. 19, 1943 Frank w. Curtis. Spring-field. Mass,

Van Norman Machine Tool Compa aslignor to I Sprintiield, Mass, a corporation of Massachusetts Application June 6, 1941, Serial No. 396.85!

11 Claims. (01.90-21) This invention relates to milling machines and in particular to hydraulic milling machines.

The main object of this invention is to provide an improved bed-type, hydraulically actuated milling machine. An additional object is to provide in a milling machine improved means for coupling a single prime mover for reciproeating the work holder and driving the spindle.

A further object is to provide an improved spindle transmission having a novel arrangement of gearing .for driving the spindle at various speeds.

Another object is to provide a milling machine in which special provision in addition to hydraulic actuation of the table is made to prevent chattering of the cutter during work removing operations.

How I accomplish the foregoing and othersnd additional objects will best be understood by a reading of the specification in conjunction with the drawings, inwhich:

Fig. 1 is a front view of machine;

Fig. 2 is'a side view of the machine of Fig. i;

Fig. 3 is an elevation partly in section on line Fig. 4 is a sectional elevation substantially on line H of Fig. 2; Fig. 5 is a sectional view on line 55 of Fig. 1;

Fig. 6 is a detail of the back of the machine sholwing a portion of the base of the machine;- an

Fig. 'l is an enlarged sectional view tially on line l--| of Fig: 4,

Referring'to Figs. 1 and 2 orthe drawings. the milling machine consists of a bed II and column ii. 'a table ll carried for reciprocation in a horizontal plane on the bed by means of ways Ii, and a axially adjustable spindle head I1 and mounted on the column on ways it cation relative to the table. An overarm I! sliding on ways 2| on "the spindle carrier is provided to support the usual pendant (not shown) for journaling the end of a tool arbor carried by the spindle 2| of'the spindle carrier. A prime mover 22, which in the machine shown is an electric motor, is carried in the bed and coupled to rotate the spindle and reciprocate the,table.

Referring to Figs. 1, 5 and 6, a cylinder 25 through the column substanis suitably mounted on the bed and contains a piston (not shown) coupled by a piston rod 2' to a lug 21 depending from the table. Hydraulic fluid is supplied to'the cylinder for reciprocation of the table from a pump 10 (Fig. 5) supl my improved milling ported in a web ii in the bed and connected directly to one end of a main driver 82 for both the table andspindle transmissions. This main driver is suitably supported on bearings in the web SI and back wall 33 of the bed as shown, and at its opposite end'beyond the back wall of the bed is provided with a pulley 34 driven by belts 35 from the drive pulley 38 of the motor 22 which also extends beyond this back wall.

Web 3| referred to above along with the walls 28 and 28 of the bed and the front wall of the bed form a reservoir from which hydraulic fluid 'is drawn through an inlet pipe, as pipe 35', to

the pump. The fluid is then delivered through an outlet pipe 36' to distributing valve mechanisms carried on the inner face of each of two panels 38 in the front wall of the bed. Panel 38 has mounted thereon. for swinging movement in an are on a shaft 40 as a pivot, a spindle manual control handle 4| which may be shifted manually to adjust the valve mechanism and thereby start and stop spindle rotation. lnthe position of the handle shown the spindle will be stationfor vertical reclproll forming part of a during working operations. Behind this flange ary while if it is swung clockwise about the spindle will rotate. Panel 38 carries a handle 45 which likewise is pivoted for swinging movement on a shaft 46 and which controls the valve mechanism associated with the panel 39.

This latter valve mechanism is connected to the pump '30 in a suitable manner by piping, for controlling distribution of fluid to the cylinder 25 to give various rates as well as directions of reciprocation to the table. Handle 45 has two extreme positions about 90 apart in arc and a number of intermediate positions. By swinging the handle to its extreme right or left positions the valve mechanism is adjusted to give respectively a rapid traverse forward orrapid traverse return movement-of the table, while the handle may be moved to intermediate positions for stopping the table or moving it at a feed rate. Adjacent to handle 01 which controls the adjustment of a throttle for manual adjustment of the speed of the table during feeding movements.

The bed at the top is provided with a flange trough to receive coolant and between the flange and ways ii for the table are provided a pair of trip plungers BI and II for automati control of the rate and direction of the table motion. These plungers are controlled by dogs 52 and 53 on the table. Plungerv II is raised or lowered by dogs 52 to mechanand 39 inserted into suitable openings 45 is a knurled knob! not ically shift the valve mechanism on panel 39 to change the rate of the table motion as well as tostop the table, while plunger BI is depressed by dog 53 to move the valve mechanism to reverse the direction of table motion. In the case of reversal of the table, the valve mechanism is shifted by a servo-motor which is supplied with fluid from the pump 30 through actuation of a servo-motor valve controlled by plunger 5|. Inasmuch as the hydraulic circuit per se does form part of this invention I will not describe in further detail the exact arrangement of parts, it being obvious that various forms of valve mechanism which are suitable for the purpose can readily be devised. One suitable arrangement is that shown in my app c ti n rial No. 391,827; filed May 5, 1941, which has matured into Patent 1942. v

Referring to Fig. 5, the main driver 32, through gears 63. drives one-member SI of a friction clutch-brake unit of well known form and sup- No. 2.302.744, of Nov. 24,

ported for rotation upon a clutch shaft 63 journaled as indicated in the web 59 located intermediate web 3I, and back wall 33 of the bed. The second member 83 of the clutch unit is suit-. ably splined on shaft 63 and may be shifted into eng ement with member 3i to cause rotation of shaft 63 bya shifter fork 38. Shifter fork 33 is fixed to one end of a shaft 31 lournaled in bosses 33 formed integrally with a partition 33 extending beneath shaft 31 and forming the top of the motor compartment (Fig. 6). At its opposlt e end shaft 61 is provided with a lever "l3 forked at its upper end and connected to the, piston rod II of a hydraulic servo-motor I2. This servo-motor is supported in web 3i and has connections I3 and 13 extending to the valve mechanism controlled by spindle control handle 3i previously referred to. The valve mechanism controls flow of liquid from the pump 33, and is arranged to direct hydraulic pressure to either a and carries for rotation therewith side of the piston of the servo-motor while exhausting fluid from the opposite side. Thus clutch shaft 63 can be either rotated or held stationary by shifting the handle 3|. For further details of one suitabl arrangement of valve mechanism reference should be had to my copending application referred to.

Suitably journaled for rotation in web 33 and the back wall 33 is a first pickoif gear shaft III provided at its front end with a gear II meshing with another gear I2 fixed to clutch shaft 63. At its opposite end, shaft in extends beyond the rear wall 33 of the bed and is provided with a pickoff gear 15 meshing with a complementary pickofl gear I6 carried on one end of a second plckofl gear'shaft i8 likewise journaled in web 59 and the back wall 33. By interchanging pickoif gears I5 and 15 on their respective shafts as well as by replacing them with gears having adiiferent ratio the speed of rotation of shaft I8 can be varied.

To prevent injury to the operator, the bed adiacent both the extending ends of the pickofl gear shafts Ill and I8 and the extending ends of the main driver 32 and motor shaft is provided with guard casings 30- and M having suitable covers 32, 33, ard 33 which may -be'opened to permit access to the ends of the shafts (Figs. 5 and 6).

Shaft 13 is coupled to drive the spindle 2i as follows; At its forward end this shaft has fixed thereto a bevel gear 85 meshing with a pair of oppositely rotating bevel gears 86 and 81,

(Fig. 2), having their hubs journaled for rotation in webs in the bed. A spline shaft 30 mounted on bearings in the spindle carrier I3 (Fig. 3). extends downwardly through the hubs of the bevel gears and has splined to it a clutch member 3| positioned between the bevel gears 33 and 81. Clutch member II is provided with clutch teeth'as shown adapted to be selectively engaged with complementary clutch teeth formed on the bevel gears .to thus impart opposite directions of rotation to the shaft 30. A cover plate 33 closes an opening in the bed adjacent the bevel gears ail-and 31 and carries a handle 33. see Figs. 2 and 5, which is pivoted on a shaft 33 carrying suitable shifter fork mechanism I33 for engaging and shifting clutch member 3| into engagement for rotation from either gear 33 or 31. v

At its upper end spline shaft 33 (Fig. 3) is provided with a bevel gear I33 which engages a bevel gear I33 having an elongated hub and journaled by bearings I31 in the spindle carrier, as shown, and at right angles to shaft 33. Mounted for sliding motion'parallel to gear I03 and in. a bore I33 ,in'the spindle carrier is a sleeve II3 of the spindle head Il. At one end this sleeve supports a gear case II2 andalso has journaled for rotation in its bore. the spindle 2I. As shown the spindle extends at one end into the gear case a gear couplet consisting of gears I I3 and I I3. Joni-naled parallel to th spindle and in bearings I23 and I2I in the gear case is a shaft I23 having one end extending through the hub of the gear I33 and splined to engage complementary splines in the hub of this gear. Intermediate bearings I23 and I2I the shaft is splined as shown and carries a shiftable gear couplet including gears I23 and I23 for respectively engaging gears III and H3 to drive the spindle at respectively a fast or a slow rate from shaft I23. To selectively engage the gears I26 and I23 a shifter fork I23 engaging the couplet as shown is suitably coupled for operation by a shifter handle I33. lee 1'18. 2.

In order to insure smooth operation of the spindle and prevent chattering, shaft I23 is extended as shown and carries a flywheel I32. This arrangement of having th flywheel mounted on shaft I 23 is of considerable advantage due to the fact that the flywheel is rotating at a constant speed regardless of whether the fast speed gears Iii, I25 or slow speed gears II3. I23 are engaged. With this arrangement the flywheel can be designed to give th best inertial effect to the spindle drive based on the speed of rotation of shaft I23 and the dynamic balance of the parts and this effect will not be affected by varying the spindle speed through shifting of gears I23, I23. This is to be differentiated from mounting the flywheel directly to the spindle where if the fiywheel gives the desired effect at slow spindle speeds it is likely to rotate fast enough to cause serious. dynamic unbalance when the speed of the spindle is increased.

From the foregoing it will be clear that the splined connection of shaft 30 with bevel gears 86 and 31 will permit "the spindle carrier to be shifted vertically on ways I3 while the splined connection of shaft I 23 rotate the screw a fixed nut I88 carried in 9. lug 181 formed preferably integrally with the spindl carrier. To suitable hand wheel I88 is fixed to the upper end thereof. As shown in Figs.

1 2 to 3, means including a sleeve I88 supported in the'spindle carrier in axial alignment with shaft 88 and interfitting with a sleeve I88 carried by the bed is preferably provided to exclude dirt and protect the operator while permitting this adjustment.

For adjustment of thespindlehead, sleeve 8' (Figs. 3 and 4) is provided with rack. teeth Ill engaged by complementary teeth I82 formed on one end of a short shaft I88 journaled in a boss I in the spindle carrier. At its lower end this shaft has fixed thereto a worm wheel I88 which -meshes with a worm I81 mounted for rotation with a shaft I48 journaled at one end in a boss I88 in the spindle carrier and intermediate its ends in acover plate I88 attached to the carrier. The shaft has asquared end as shown to which may be applied a handle for turning the shaft.

As shown in Figs. 3 and 4, the spindle head I1 [and overarm I8 may each 'be locked in their adjusted positions by' binders I88 and I". Binder I88 consists of a bolt I88 having at one end an enlarged head I88 provided with a squared end with the head I88 fitting within a bore I8'I extending transversely above the sleeve |I8.- At its opposite end the bolt is threaded into a cylindrical nut I88 positioned in the bore beyond the axis of the sleeve and has slidable thereon'a'coilar I89 located between the enlarged head I88 and the axis of the sleeve II8. By tightening the bolt, the nut I88 and collar I89 are drawn into frictional engagement with the sleeve 8. v

. In the case' of the overarm binder IN, a short shaft I18 having a squared end is provided with two concentric bearing surfaces I18 and I18 which are journaled as shown in a bore in the spindle carrier. Intermediate thebearing surfaces, this shaft has an integral eccentric I88 engaging'a slot in a connecting rod l88f vertically slidable in a slot in the spindle carrier. At its upper end, this connecting rod extends into arm and has threaded thereto a nut I88. This supported on the column for vertical movement,

a spindle in the carrier and mounted for axial movement with respect to the carrier, a table carried on the bed for reciprocation transversely "to the axis of the spindle, a prime mover in the bed, a main drive shaft driven from the prime mover, an hydraulic transmission for said table and including a pump coupled directly to the end of the main drive shaft, and a spindle transmission driven from the main drive shaft and driving the spindle, said spindle transmission comprising; a first and second shaft, a first and second spline shaft, clutch means on the firstshaft for selectively coupling said shaft for rotation from the main driveshaft, change gearing connecting the first and second shaft for rotation and including pick-off gears, a spindle reversing clutch mechanism connecting the second shaft and said first spline shaft for opposite directions of rotation of the latter, gearing between said first and second spline. shafts, and change speed gearing connecting said second spline shaft and the spindle.

2. In a milling machine, a bed, a column extending upwardly from the bed, a spindle carrier supported on the column for'vertical movement,

\ a spindle in the carrier mounted for axial movea cavity IBI formed in the bottom of the overnut engages with its under surface a shoe- I88 which in turn engages as at I88 with shoulders in the overarm. By rotating shaft I18, connecting rod I88 will draw the shoe downwardly forcing the overarm against the ways 88 in the spindle carrier.

Among theadvantages due to the structure disclosed-is the separa'tionin the bed of the mechanical spindle transmission and hydraulic table transmission. Thus, referring to Fig. 5, the

, web 8|, the back wall, 88,and the side walls 288 and 28l of the bed along with the partition 88, form a mechanical transmission compartment while the web 8| along with walls 88, and 88 and the front wall of the bed forms a sump for the hydraulic pump 88. i

with the arrangement shown, lubricant in the mechanism transmission compartment is comment with respect to the carrier, a table carried on the bed for reciprocation transversely to the axis of the spindle, a prime mover in the bed,

'a main drive shaft driven from the prime mover,

an hydraulic transmission for the table and including a pump coupled directly tothe end of the main drive shaft, and a spindle transmission driven from the main drive shaft and driving the spindle, said spindle transmission comprising; a first and second shaft, 9. first and second spline shaft and the spindle in the order named, clutch means on the first shaft for selectively coupling said shaft for rotation from the main drive shaft,

change gearing connecting the first and second shaft for rotation and including pick-off gears,

a spindle reversing clutch mounted on the first spline shaft and connecting the second shaft and said first spline shaft for opposite directions of rotation of the latter, gearing between said first pletely isolated from the sump for the hydraulic pump 88 and there is no danger of comingling of the two. This desirable result is further in-- sured by having both the pump 88 and the servomotor '|2 supported. in the web 8| with their connecting pipes 852.88, 18 and .18 located in the sump.

Another advantage is in the provision in the spindle transmission'of the reverser consisting and second spline shafts, a flywheel carried on said second spline shaft, and change speed gearing between the second spline shaft and the spindle.

3. In a milling machine, a bed, a'column extending upwardly from the bed, a spindle head carrier supported-on the column for vertical movement, a spindle. head mounted in the car- 'rier and adjustable transversely of the direction or carrier movement, a spindle supported in the spindle head with its axis parallel to the direction of spindle head adjustment, a table carried on the bed for reciprocation transversely to the axis of the. spindle, a prime mover inthe bed, a main drive shaft driven from the prime mover, an hydraulic transmission for said table and including a. pump coupleddirectly to the end of the main drive shaft, and a spindle transmission driven from the main drive shaft, said spindle transmission comprising; a first and a second shaft in the bed, a first spline shaft carried in the spindle carrier and slidable with respect to the bed, a second spline shaft mounted in the spindle head and slidable with respect to the spindle carrier, and the spindle, clutch means on the first shaft for selectively coupling said shaft for rotation from the main drive shaft, change gearing connecting the first and second shaft for rotation and including pick-off gears, a spindlereversing clutch mechanism mounted in the bed and splined to the first spline shaft and selectively connecting the second shaft and first spline shaft for oppositedirections of rotation of the latter, gearing mounted in the spindle carrier and splined to the second spline shaft and connecting the first and second spline shafts, and change gearing carried by the spindle head and connecting the second spline shaft and the spindle.

4. In a milling machine, a bed, a column extending upwardly from the bed, a spindle head carrier supported on the column for vertical movement, a'spindle head mounted in the carrier and adjustable transversely to the direction of carrier movement, a Spindle in the spindle head, a table carried on the bed for reciprocation transversely to the axis of the spindle, a prime mover in the bed, a' main drive shaft driven from the prime mover, an hydraulic transmission for said table and including a pump coupled directly to the end of the main drive shaft, and a spindle,

transmission driven from the main drive shaft, said spindle transmission comprising; a first and a second shaft in the bed, a first spline shaft carried in the spindle carrier and slidable with respect to the bed, a second spline shaft mounted in the spindle head and slidable with respect to the spindle carrier and the spindle, clutch means on the first shaft for selectively coupling said shaft for rotation from-the main drive shaft, change gearing connecting the first and second shaft for rotation and including pick-oil gears, a spindle reversing clutch mounted in the bed and selectively connecting the second shaft and first spline shaft for opposite directions of rotation of the latter, gearing mounted in the spindle carrier in slidable relation to the second spline shaft and connecting the first and second spline shafts, a fiywheelmounted in the spindle head and carried by the second spline shaft and change gearing carried by the spindle head and connecting the second spline shaft and the spindle.

5. In a milling machine, shed, a column extending upwardly from the bed, a spindle carrier mounted on the column for vertical movement, a spindle in the carrier mounted for axial movement with respect to the carrier, a table carried on the bed for reciprocation transversely to the axis of the spindle, a prime mover in the bed, a main drive shaft driven from the prime mover, an hydraulic transmission for said table andincluding a pump coupled directly to the end of the opposite directions of rotation of the latter, gearing between the first and second spline shafts and change speed gearing connecting said second spline shaft and the spindle.

6. In a milling machine, a bed, a column extending upwardly from the bed, a spindle head carrier mounted on the column for vertical movement, a spindle head mounted in the carrier, a spindle in-the spindle head, the spindle head being adjustable transversely of the direction of motion of the spindle carrier to move the spindle axially, a table supported on the bed for reciprocation transversely to the axis of the spindle, a prime mover in the bed, a main drive shaft driven from the prime mover, an hydraulic transmission for the table and including a pump coupled directly to the end of the main drive shaft, and a spindle transmission driven from the main drive shaft and comprising; a first and a second shaft in the bed, a first spline shaft supported in spindle carrier and extending into the bed. in slidable relation thereto, a second spline shaft mounted in the spindle head and slidable with respect to the spindle carrier and the spindle, clutch means on Y the first shaft for selectively coupling said shaft for rotation from the main drive shaft, an hydraulic servo-motor for said clutch and operated by fiuid from the pump, change gearing connecting the first and second shaft for rotation and including pick-off gears, a spindle reversing clutch mounted in the bed and selectively connecting the second shaft and the first spline shaft for opposite directions of rotation of the latter, gearing mounted in the spindle carrier in slidable relation to the second spline shaft and connecting the first and second spline shafts and change gearing carried by the spindle head and connecting the secondspline shaft and the spindle.

7. In a milling machine having a bed, a column extending upwardly from the bed, a table supported for reciprocation on the'bed, a spindle carrier supported on the column for vertical reciprocation and a spindle in the carrier supported for axial adjustment transversely to the direction of table reciprocation; an hydraulic fiuid sumpand a spindle transmission compartthe latter ment in the bed and separated by a dividing wall,

an hydraulic transmission for reciprocating the table including a pump secured to said wall and extending into the sump, a spindle transmission for rotating the spindle and in part located in the compartment. a main drive shaft in the compartment and having one end extending through said wall and directly connected to the pump for rotating the same, connections between the main drive shaft and spindle transmission for driving and including a spindle clutch in the compartment, an hydraulic servo-motor for. operating said spindle clutch and supported on said wall and extending into the sump and connections within said sump for directing fluid to and f from said servo-motor.

main drive shaft, and a spindle transmissiondriven from the main shaft, said spindle trans: mission comprising; a first and a second shaft, a first and a second spline shaft and the spindle in the order named, clutch means on the first" necting the second shaft andfirst spline shaft for 8. In a milling machine having a bed, a table reciprocably mounted on the bed a column, a spindle carrier vertically movable on the column, a spindle head. horizontally adjustable in'the spindle carrier transversely of the table, and a spindle in the head; a prime mover, speed change gearing in the bed, a vertical shaft extending from the.bed to the spindle carrier and having an extensible connection, a horizontal shaft on the spindle carrier, gearing connecting the vertical shaft with the changespeed gearing and with the horizontal shaft, afiywheel on the horizontal shaft, and change speed gearing between the horizontal shaft and the spindle.

9. In a milling machine having a bed, a table reciprocably mounted on the bed, a column, a spindle carrier vertically movable on the column, a spindle head horizontally adjustable in the spindle carrier transversely of the table and a.

spindle in the spindle head; a prime mover'in the bed, and a spindle transmission connecting the prime mover and the spindle and including a reversing clutch in the bed, change speed gearing connecting the prime mover and reversing clutch and gearing in the spindle head connecting the reversing clutch and the spindle including a pair of relatively slidable gear clusters.

10. In a milling machine having a bed, a table 'reciprocably mounted on the bed, a column, a spindle carrier vertically movable-on the column, a spindle head horizontally adjustable in the spindle carrier transversely to the table and a 1 driver and including a 'pump' directly connected spindle in the spindle head; a prime mover in the bed and a spindle transmission connecting the prime mover and the spindle and including a reversing clutch and a motion interrupting clutch in the bed, gearing connecting the motion interrupting clutch and the prime mover, change speed gearing connecting the motion interruptto the main driver, a spindle transmission driven from the main driver and including a motion interrupting clutch connected to the main driver,

a reversing clutch, change speed gearing cennecting the reversing clutch and motion interrupting clutch, change speed gearing in the spindle head connected to drive the spindle, and connections between the last mentioned change speed gearing and the reversing clutch, fluid operated power means for engaging the motion interrupting clutch and connections for operating said power means from the pump.

FRANK w. corms. 

